Multi-angle gauge



June 4, 1963 w. D. HUSTON ETAL MULTI-ANGLE GAUGE 2 Sheets-Sheet 1 Filed Nov. 4, 1960 INVENTORS WILLIAM D. HUSTON AND RICHARD A. BEISHEIM Atfomy( June 4, 1963 w. D. HUsToN ETAL 3,091,966

MULTI-ANGLE GAUGE Filed Nov. 4, 1960 2 Sheets-Sheet 2 FIG. 5

FIG. I

INVENTOR. WILLIAM D. HUSTON AND I4 BY RICHARD A. BEISHEIM After-nf] f United States Patent O 3,091,966 MUL'H-ANGLE GAUGE William D. Huston, Rochester, and Richard A. Beisheim,

Spencerport, NX., assignors to Rochester Manufacturing Company, Inc., Rochester, NY., a corporation of New York Filed Nov. 4, 1960, Ser. No. 67,287 7 Claims. (Cl. 73-362.2)

'I'he present invention relates to gauges, and more particularly to dial type gauges such as are employed yfor measurement of temperature or pressure.

The conventional dial gauge has a head containing a graduated dial and a pointer which is movable relative thereto, and it has a stem containing the means to move the pointer over the scale in response to variations in the condition to be measured, such as variations in temperature or pressure. The head and stem are usually secured to one another. However dial thermometers, as well as dial pressure guages are likely to be mounted in many different positions to suit the convenience of the particular job on which they are installed. As a result, the manufacturer has had to manufacture a number of different types of dial gauges and thermometers to meet industrial requirements. For instance if a thermometer had to be placed overhead, the dial gauge had to be built so that the dial tilted downwardly so that it could be read; if the thermometer was to be mounted below the normal line of vision, the dial gauge had to be built so that the dial tilted upwardly, etc.

Efforts have been made in the past to provide multiangular gauges; but any multi-angular gauges, with which we are familiar, have not proved satisfactory in practice because they were not accurate; when the head was tilted with reference to the stem of the gauge, the calibration between the head and the stem was thrown enough o whereby aiecting the accuracy of the reading in the tilted position of the head.

The primary object of the present invention is to provide a dial gauge which has a multi-angular connection between the stem and the dial so that the stem can be placed in substantially any position in accordance with the requirement of a particular installation, and the head can be tilted, after installation of the stem, so as to place the dial in a conveniently readable position.

Another object of the invention is to provide a gauge having a head that can be tilted with reference to the stem, after installation of the stem, without aecting the accuracy of reading of the gauge.

Another object of the invention is to provide a gauge of the character described which will be of simpler construction than previously known multi-angular gauges, and will be less costly to manufacture.

Another object of the invention is to provide a gauge of the character described which will have a neat appearance, be rugged, and be susceptible of mass production.

Another object of the invention is to provide a gauge of the character described wherein the thrust imposed upon the drive and driven shafts of the gauge in the tilted position of the head remains essentially constant regardless of the angle between these shafts.

Other objects of the invention will be apparent hereinafter from the specification and the claims, particularly when read in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is a fragmentary plan view of a temperature gauge or thermometer constructed according to one embodiment of this invention;

FIG. 2 is a fragmentary section through this gauge taken on the line 2-2 of FIG. l looking in the direction of the arrows;

FIG. 3 is a `fragmentary vie-w taken at right angles to FIG. 2 and showing the stem and the means for securing the gauge head in any angularly adjusted position in one plane;

FIG. 4 is a fragmentary view of the parts shown in FIG. 3 and showing additionally fragmentarily the gauge head, the gauge head being tilted from the position shown in FIG. 3; and

lFIG. 5 is a diagram showing the loc-us or path of the coupling between the input and output shafts of the gauge for different included angles.

In the embodiment of the invention illustrated, the head of the gauge is connected to the stem by a coupling which includes two members, one of which is rotatable through an angle of 360 relative to the head, and the other of which is rotatable through an angle of 360 relative to the stem; one of which is forked to receive the other; one of which has two arcuate cam slots in each furcation that are curved about respectively different centers and the other of which has pins which ride in these cam slots. In the illustrated embodiment of the invention a thermometer is shown which has a bi-metallic sensing element mounted in the stem, that is connected to the pointer of the gauge by a flexible coil spring. A bellows which connects the head with the stem, surrounds this spring to protect and conne the same. With this construction, the head can be adjusted through 90 in one plane, and through 360 in another plane.

Refering now to the drawings by numerals of reference, 10 denotes a temperature gauge or thermometer constructed according to one embodiment of this invention. This gauge comprises a head 11 and a stern 12. The stem includes an adapter bushing 13 which is externally threaded to thread into a wall or tank opening or other opening in which the gauge is to be mounted. Fastened in the bushing 13 as by a pressed lit, welding, or soldering is a tube 14, in which is mounted a helicallywound lai-metallic element 16.

The head comprises a generally cupshaped casing 18 which is formed at its top with an outwardly-projecting flange portion 19. yMounted in the casing is a flat plate or disc 20. The disc 2.0 has an inverted ring-shaped member 21 surrounding it, which has an inturned ilange portion that serves as a seat for a transparent cover glass 22. The member 4Z1 has tongues 23 struck downwardly from its ange portion which engage against the front face `of the disc 20 to serve as spacers and to stiften the member 21 and support the glass. The glass is held in position by a :bezel Z5 which has an inturned portion engaging against the front face of the glass, and which is secured to the llange 19 of the casing by screws 26.

The disc Z0 is suitably graduated on its front face, and is rotatably adjustable for calibration of the instrument by rotation of a shaft 27. This shaft carries a pinion 28 which meshes with a gear 29 that is riveted to the back of disc 20 centrally thereof. Shaft 27 is journaled in a bushing -or plug 30 which is fastened in the rear wall of casing 18.

Riveted in a hole disposed centrally of the rear wall of the casing is a plug or adapter 32, in which are [fitted the spaced bushings 33 and 34', in which there is journaled a shaft or stem 35. A pointer 36 is secured to the front end of this 4shaft to read against the graduations on the plate 20.

The lai-metallic coil 16 is brazed or otherwise secured to a shaft 37 which is the input shaft of the instrument and which is journaled adjacent opposite ends in bushings 3S and 39 that are -mounted in axially-spaced relation in the tube 1d.

The shaft 37 is connected to the shaft 35 to transmit torque thereto by a coil 4spring 40. This spring is fastened at one end to -a 4bushing 4l that is secured to the front end of the shaft 37; and it is threaded on and fastened at its other end to a bushing 43 which is 'fasten-ed to shaft 35. This spring is wound on edge so that it is stiff in torque but flexible in length.

Mounted on the adapter l?. is a bracket 45, which has an inturned collar or llange do formed at its lower end that engages in a peripheral groove 47 formed in this adapter l2. The adapter 52 carries a second bracket 5i), which has an inturned collar or flange 5l at its upper end that vengages in a peripheral recess or groove 52 formed in this adapter 32..

In order to maintain a fixed relation between the pointer and the scale and thus to preserve its calibrated accuracy, the head is connected to the stem so that it cannot twist about the axis of the stem while being allowed to tilt relative thereto. The connecting element is a hollow bellows 42 which is iieXible longitudinally but resists twist, that is, is rigid in torque. The bellows may be welded or otherwise anchored at its ends to the blocks or adapters i3 and 30; and it ssurrounds spring 40.

The bracket 45 is furcated and has two parallel arms 53. The bracket 50 is also furcated and has two parallel arms 54 which are disposed inside the arms 53 to abut thereagainst. Each of the arms of the bracket 45 is formed with two arcuate slots 57 and 53, which are curved respectively about different centers. Mounted in each arm of the bracket 50 is a headed screw 60. The Shanks of these screws engage in the slots 5S. Riveted in the arms l.tie of the bracket 50, also, are headed screws 6l which engage in the slots 57.

A screw 63, which is adapted to thread into aligned holes 64 in juxtaposed arms 53 and S4 of the brackets, serves to hold the brackets against movement relative to one another during shipment of the instrument.

The brackets 45 and `50 have, respectively, generally keyhole shaped slots in their bottom and top walls, respectively, by means of which the brackets may be slid into the grooves 47 and 52, respectively, in the adapters t3 and 32 to engage them with the adapters. The brackets 45 and 50 are adapted to be clamped to the respective adapters 13 and 32 in any adjusted position by clamping screws 67 and 68, each of which passes through a hole in one arm 53 or 54, respectively, of the associated bracket and threads into the other -arm 53 or 54 of the associated bracket. When the screws 67 and 63 are released the brackets 45 and 50 can be adjusted together as a unit about the axis of shaft 37 to position the head l1 angularly in one plane.

To adjust the head angularly in a plane at right angles to the aforementioned plane, screws 60 are released, and bracket 50 is swung to the desired position relative to bracket 45. In this adjustment pins 61 ride in slots 57 and screws 6@ ride in slots 5S. After the adjustment is effected, screws 60 are tightened again to secure the bracket 50 in adjusted position. FIG. 4 shows the bracket 50 and head 11 adjusted in a plane containing the axis of shaft 37 to a position 90 from the position shown in FIGS. 2 and 3.

In the adjustment of head l1 in a plane containing the axis of shaft 37 it is desirable to maintain the length of the spring 40 -constant at all times. `Otherwise it will transmit, at different angular positions of head il, difterent .amounts ci turning movement to shaft 35 for a given amount of rotation of shaft 37; and the gauge will not register accurately at all positions of adjustment of the head.

FIG. 5 illustrates diagrammatically how the connection or coupling of the present invention permits the head to be adjusted angularly with reference to the stem Without aiecting the accuracy of the instrument. iin this figure, A denotes the lower end of the spring 40. In other words, A is the top edge of the bushing 41. The top end of the spring at the lov/er end of the bushing 43 is aligned laterally with pins el (FIG. 2). Thus the top end of the spring follows a curve corresponding to the curvature of slot 57. H (PEG. 5) denotes this curve; and F designates the curvature of the other cam slot, slot 5S. Curve H controls tho position of lbushing 43, that is, of the upper end of spring dit. Curve F controls the direction of the lspring at this end. 49D 4th, 402, 403, 404, 405, 406, 4537, 408 and 409 denote, respectively, different positions of the spring 40 as the output shaft 35 is swung from a position of alignment with the input shaft 37 (the position shown in FIG. 2) through a position where the axis ofthe output shaft `extends at to the axis ofthe input shaft (the position shown in FIG. 4) to a position, denoted at 351' in FIG. 5 where the axis of the output shaft is parallel to the axis of the input shaft 37. H0, H1, H2, H3, H4, H5, H6, H7, H8 and H9, respectively, denote positions along arc H of the upper end of the spring 40 for the different shown positions of the spring. F1, F2, F3, F4, F5 and F5 denote corresponding positions along arc F.

The positions on vF are obtained by projecting the points H0, H1, etc. to arc F, the lines of projection for the several points being lines perpendicular to the tangents to the spring curves 400, 401, etc. at the different points on curve H. The object of the invention is to maintain the length of the spring 40 constant in the diierent angulm positions of the output shaft. As the angle between the shafts' changes, in order to maintain `a uniform length of the spring, the upper end of the spring should follow a path such as the path H which is the locus of the free end of the spring as it changes its radius of curvature. The curve can be defined as the relation where rx is the radius of the yarc of the spring at a given angle; r1 is the radius of the iicxible coupling at a 90 angle and go is the angle sub-tended by the arc of the flexible coupling or spring.

With any multi-jointed or continuously flexible variable coupling, if the input and driven shafts can be positioned in relation to each other to follow `a curve represented by this relationship, the ends of the shafts will remain in a tlixed position in relation to the ilexible coupling. There will be a `minimum of side thrust against the two shafts. The ieXible coupling d0 will Aform a true circular arc and position itself lfreely without strain. It will be noted that the portion of arc H between positions H0 and H5 closely approaches a circular arc curved about G, and that correspondingly the portion of arc F between positions 'F0 and F5 closely approaches a circular arc curved about point E. For .a gauge which is to be adjusted only through .an angle of 90, then, the slots 57 and `58 may be yof circular arcuate curvature. Actual tests show that, when arcuate slots, such as shown at 57 and 58, are used to guide the head l1 Vin its angular adjustment relative to the stern 12, the maximum deviation of shaft 35 iront correct position for any angular position of head 11 is less than 1- 1%. It the two slot-s 57 and 58 are made true cam slots, however, any degree of perfection can be obtained. The Walls of these slots control .the followers 60 Iand 61 and can be made to the highest precision to generate a curve during adjustment of the head 111 which will conform exactly to the lformula given above, or which will approach as nearly as desired thereto. With the adjustment mechanism of the present invention it is possible to achieve the ideal curve, or to approach that curve within all practical limits, as distinct from the mountings of the prior art which -could only remotely approximate the required curve.

While the invention has been described in connection with a specific embodiment thereof, then, it will be understood that it is capable of further modication, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the

principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features he-reinbefore set forth, and as fall within the scope of the invention or the limits of the appended claims.

Having thus described our invention, what -we claim is:

l. A gauUe comprising a support, a first shaft journaled in said support, condition-responsive means for rotating said first shaft, -a head, a graduated dial mounted in said head, a second shaft journaled in said head, a pointer secured to said second shaft lfor rotation relative to said dial, a coil spring operatively connecting the two shafts to transmit torque from said rst shaft to said second Shaft, and means for supporting said head from said sup port for angular adjustment of said head relative to said support comprising a first bracket secured to said support, a second bracket secured to said head, and separate means connecting the two brackets together and controlling their relative movements so that a compound movement of one bracket relative to the other is effected simultaneously about two different parallel axes which are displaced from one another and -both of which extend at right angles to the axis of said rst shaft.

2. A gauge as claimed in claim 1 wherein the positionsl of said two different axes are selected so that the length of said spring remains approximately -constant in all positions of adjustment through an angle of 90 of said head relative to said support.

3. A gauge comprising a support, a first shaft journaled in said support, condition-responsive means for rotating said first shaft, a head, a Vgraduated dial mounted in said head, a second shaft journaled in said head, a pointer secured to said second shaft for rotation relative to said dial, a coil spring operatively connecting the two shafts to transmit torque :from said first shaft to said second shaft, and means for supporting said head from said support for angular adjustment of said head relative to said support comprising a first bracket secured to said support, a second bracket secured to said head, one of said brackets having a pair of arcuate slots therein curved, respectively about different axes, each extending at right angles to the axis of said -iirst shaft, and two guide mem- -bers carried by the other :bracket engaging, respectively, in the two slots to control angular movement of one bracket relative to the other in one plane.

4. A gauge as claimed in claim 3, wherein the positions of the axes of curvature of said slots are selected so that the length of said spring remains approximately constant in all positions of adjustment through au angle of of said head relative to said support.

5. A gauge as claimed in claim 3, wherein the two brackets are mounted on said support and said head, respectively, for rotatable adjustment about axes extending at right angles to said different axes.

6. Apparatus comprising a support, a drive shaft journaled in said support, means for rotating said drive shaft, a head, a driven shaft journaled in said head, a flexible coupling connecting said drive and driven shafts to transmit torque from said drive shaft to said `driven shaft, and means connecting said head and said support for angular adjustment of said head on `said support about an axis extending at right angles to the axis of said drive shaft and comprising -a guide member and a follower, one of the two last-named parts being secured :to said head to move therewith, and the other of the two last-named parts being secured to said support, said guide member having a cam-type guide surface and said follower engaging and riding on said guide surface, and said guide surface being shaped to maintain a constant length of arc in said coupling `as said head is adjusted angularly relative to `said support.

7. Apparatus as claimed in claim 6 wherein said flexible coupling comprises a coil spring, one end of which is secured to said drive shaft, and the other end of which is secured to said driven shaft, and wherein said guide surface is shaped so that the radius rx of said spring at any angle of adjustment between and 90 of said driven shaft relative to said drive shaft conforms to the formula:

where r1 is the radius of said spring when the driven shaft is atan angle of 90 to the drive shaft and :p is the angle subtended by the arc of the iiexible coupling.

References Cited in the file of this patent UNITED STATES PATENTS 2,925,734 Gorgens Feb. 23, 1960 

6. APPARATUS COMPRISING A SUPPORT, A DRIVE SHAFT JOURNALED IN SAID SUPPORT, MEANS FOR ROTATING SAID DRIVE SHAFT, A HEAD, A DRIVEN SHAFT JOURNALED IN SAID HEAD, A FLEXIBLE COUPLING CONNECTING SAID DRIVE AND DRIVEN SHAFTS TO TRANSMIT TORQUE FROM SAID DRIVE SHAFT TO SAID DRIVEN SHAFT, AND MEANS CONNECTING SAID HEAD AND SAID SUPPORT FOR ANGULAR ADJUSTMENT OF SAID HEAD ON SAID SUPPORT ABOUT AN AXIS EXTENDING AT RIGHT ANGLES TO THE AXIS OF SAID DRIVE SHAFT AND COMPRISING A GUIDE MEMBER AND A FOLLOWER, ONE OF THE TWO LAST-NAMED PARTS BEING SECURED TO SAID HEAD TO MOVE THEREWITH, AND THE OTHER OF THE TWO LAST-NAMED PARTS BEING SECURED TO SAID SUPPORT, SAID GUIDE MEMBER HAVING A CAM-TYPE GUIDE SURFACE, AND SAID FOLLOWER ENGAGING AND RIDING ON SAID GUIDE SURFACE, AND SAID GUIDE SURFACE BEING SHAPED TO MAINTAIN A CONSTANT LENGTH OF ARC IN SAID COUPLING AS SAID HEAD IS ADJUSTED ANGULARLY RELATIVE TO SAID SUPPORT. 